ML25162A255
| ML25162A255 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 06/11/2025 |
| From: | Samson Lee NRC/NRR/DORL/LPL4 |
| To: | Lee N Wolf Creek |
| Lee S, 301-415-3168 | |
| References | |
| EPID L-2025-LRO-0009 | |
| Download: ML25162A255 (1) | |
Text
From:
Samson Lee To:
ext_Joshua_Turner Cc:
Nathan Lee
Subject:
Request for additional information: Wolf Creek results of steam generator tube inservice inspection during the 26th refueling outage (EPID: L-2025-LRO-0009)
Date:
Wednesday, June 11, 2025 1:24:00 PM
Background
By letter dated November 1, 2024 (Agencywide Documents Access System (ADAMS)
Accession Number ML24306A219), Wolf Creek Nuclear Operating Corporation (the licensee), submitted information summarizing the results of the 2024 steam generator (SG) tube inspections performed at Wolf Creek Generating Station (Wolf Creek) during refueling outage26 (RF26).
Based on its review of the submittal, the U.S. Nuclear Regulatory Commission (NRC) staff determined that, to complete its review, it needs a response to its request for additional information (RAI) below. The NRC staff may have additional RAIs. The licensee staff determined that a draft RAI clarification call was unnecessary. The licensee staff requested, and NRC agreed, to an RAI response by June 30, 2025.
The NRC staff considers that timely responses to RAIs help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources. If circumstances result in the need to revise the agreed upon response date, please contact Samson Lee, NRC Project Manager, at (301) 415-3168 or via email Samson.Lee@nrc.gov.
Regulatory Basis The submittal is based on Section 5.6.10 in the Wolf Creek Technical Specifications, which requires that a report be submitted within 180 days after the initial entry into hot shutdown (MODE 4) following completion of an inspection of the SGs.
The NRC staff of the Chemical, Corrosion, and Steam Generator Branch of the Division of License Renewal has reviewed the information the licensee provided and determined thatadditional information is required to complete its review of the inspections. Therefore, the NRC staff requests the following additional information:
Question
- 1. The RF26 SG tube inspection report states in the table on page 1 that the inspection addresses degradation mechanism sub-populations, such as potential high residual stress tubes and outside diameter stress corrosion cracking (ODSCC) at dings/dents.
However, the report does not indicate whether the tube in SG A that was found with axial ODSCC at a dent/ding was a tube with potentially high residual stress.
- a. Provide the residual stress status of the tube in Row 55 Column 46 of SG A (i.e., whether it is a tube with potentially high residual stress).
- b. Provide the number and location of in-service tubes in each SG that have potentially high residual stress.
Docket No. 50-482